Transformer construction



Dw 1934- H. BUTLER ET AL 1,983,657

' TRANSFORMER CONSTRUCTION FiledDec. 20, 1953 I -E l L 3. 12215 hmm I :1. E E

U] LLJ U m D 0.0: 0.1 L0 l0 I00 200 FREQUENCY IN KCS. INVENTORS HEIIIH R. Butler dnlm L. Westun BY #ORNEY Patented Dec. 11, 1934 PATENT OFFICE 1,983,657 TRANSFORMER CON STRUCTION Henry E. Butler, Verona, East Orange, N. J., assi Inc., New York, N. Y., ware Application December 20,

14 Claims.

Our invention pertains in general to transformers and specifically relates to a construction of transformer of high quality characteristics.

The transformer construction of our invention 6 is particularly adapted for'use in systems requiring the transmission of extremely wide bands of frequencies as well as operation between different impedance levels. Such requirements are particularly characteristic of television transmission equipment in which very wide bands of frequencies are employed, and in which it is usually necessary to transmit such wide bands of frequencies from one geographic point to another such as from the scanning apparatus to the transmitter. In order to meet the requirement for an electron tube amplifier capable of passing a band of frequncies of the width used in television such as from a few cycles per second up to several hundred kilocycles per second, it has heretofore been customary to employ resistance coupling between the electron amplifying tubes. This type of coupling meets the requirement for wide band transmission to some extent, but has certain serious defects, particularly in that it is impossible to work from one impedance level into another thereby making transmission of frequencies from one point to another extremely diflicult.

The principal object of our invention consists in providing an eflicient construction of coupling device for transferring wide bands of frequencies with great fidelity between different impedance levels.

Another object of our invention comprises providing a closed core transformer capable of passing wide bands of frequencies without appreciable distortion or loss.

A still further object of our invention comprises providing a construction of transformer employing high potential and low potential windings with disproportionate allocation of turns of the windings in an inter-leaved construction for accomplishing the transmission of frequencies over a greatly extended frequency range.v

These and other objects will be apparent from the following specification, reference being had to the accompanying drawing in which like reference numerals designate corresponding parts throughout, and in which:

Fig. 1 is an elevation and partially sectioned view of one embodiment of the transformer con-. struction of our invention;

Fig. 2 is a partial side elevation corresponding to the view of Fig. 1; and

Fig. 3 is a logarithmic representation of the and John L. Weston, gnors to Wired Radio, a corporation of Dela- 1933, Serial No. 703,180

transmission characteristic of the transformer construction according to our invention.

Our invention contemplates, in one aspect, the provision of a transformer construction having a magnetic core with inter-leaved primary and 5 secondary windingsdivided into symmetrically balanced groups with the lower potentials adjacent the core. Such a construction is particularly suited for use in balanced amplifiers, although our invention is not to be limited in this respect. It is an especial feature of our invention that the high potential portion of the windings are disproportionately allocated so that a larger number of turns of wire used in the winding will be found in a particular section of the interleaved parts of the winding.

Referring to the drawing in detail, and particularly to Fig. 1, the laminated core structure 1, built up of inter-leaved E-shaped laminae, is provided about its middle section 2 with the usual insulation layer 3. As shown in Fig. l, the left-half of the middle portion 2 of core 1 is provided with a winding 4. A similar winding 10 is disposed upon the right-hand part of the middle portion 2 of core 1. Next upon the windings 5 4 and 10 are respectively provided windings 5 and 11, as'shown, it being understood that proper insulation is provided as required. Above the winding 5 are provided other windings 6, '7, 8, and 9, and above the winding 11, windings 12, 13, 14, and 15 are provided. The windings 9, 7, 5, and the windings 15,13, and 11 form the high potential system of the transformer. These two groups of windings respectively disposed upon the right and left hand sides of the core are conductively interconnected as shown in the drawing. Wires 16 and 17 form the high potential terminals for the transformer and are respectively connected to the high potential ends of the windings 9 and 15. The other extremity of winding 9 is connected to the high potential side of winding 7 while the other end of winding 7 is connected to the high potential side of winding 5, the other terminating portion of the winding 5 being connected low potential side of winding 11. The other end of winding 11 is then connected to the low potential side of winding 13, the other terminating end of which is connected with the low potential side of winding 15.

The group of windings 8, 6, and 4, and the group of windings 14, 12 and 10, form two symmetrical and balanced groups comprising the low potential system of the transformer as a whole. Connection 20 is connected with the high potenthrough a connection 18 to the 45 will be noted that an area of insulating covering 26 is provided externally of tial side of winding '8,

system of the transformer the other end of winding 8 being connected with the high potential side of winding 6. The terminating or low potential side of winding 6 is connected with the high potential side of winding 4 and the other end of winding 4 is cou led through a connection 23 to the low poten ial side of winding 10. The higher potential or other end of winding 10 is connected with the low potential end of 12, the higher potential end of winding 12 being connected :with the low potential end of winding 14. The wires 20 and 21 form the low potential terminals of the transformer as a whole.

The wires 18 and 23 are provided with connections 24 and 25 respectively for obtaining the substantially zero transmitted potential connections to the windings of the transformer for use in balanced amplifiers and similar circuits. It insulation, shown as an air gap, exists between the two groups of windings 4-9 and 10-15, respectively. A proper the two groups of windings as shown.

The left-hand and right-hand groups of windings are respectively inter-leaved, and the zero potential areas are substantially adjacent the middle portion 2 of core 1. It is an especial feature of our invention that a-large portion of the total number of turns in the high potential is allocated to a restricted portion of the total winding area. As shown in Fig. 1, the winding 9 has substantially twice the number of turns of wire as that in the other primary windings in the group of which winding 9 is a struction of transformer in accordance with the principles of our invention, the windings 5 and 7 were each of 300 turns of wire while the winding 9 was of 600 turns, the corresponding wind;- ings of the right-hand group being of the same number of turns. In this same construction, the secondary win'dingsfi, 6, and i, as well as the secondary windings 14, 12, and 10 were each of 40 turns, the wire employed in the high potential windings in this particular construction being enameled copper, B and S. gauge, No. 38, and the wire employed in the low'potential windings being enameled copper, B. and S. gauge, No. 25.

It will be understood that proper insulation is provided as required. The representation of the windings of the upper half of the transformer in Fig. 1 is essentially sectional, the delineation of every wire being omitted for simplicity and clarity in the drawing. It will be further understood, of course, that in this embodiment the turns of wire are layer-wound and encircle the middle portion 2 of core 1. Other types of wind ings may be used, when indicated. In constructing a transformer of the type disclosed, it must be constantly borne in mind that the greatest care must be continuously exercised in the fabrication of the entire structure. Y

With such a transformer connected in a balanced amplifier for coupling purposes it is possible to obtain the accurate transmission of a wide band of frequencies with great fidelity. For example, the curve A of Fig. 3 representsthe transmission characteristics of the present form of our transformer employed in such a system. It will be seen that the curve is substantially flat except for very slight variations at its exmeans? windin part. For example, in one conpotential systems being constructed in accordance with our invention possesses great utility and offers many advantages in the art. It will be at once apparent that a transformer with such characteristics is of great importance in many fields of endeavor, especially in television where it is highly desirable to transmit a wide band of frequencies between different impedance levels.

' Although we have described our transformer in a certain preferred construction it will of course be obvious" that manyv changes may be made without departing from the intended scope of our invention. We do not, therefore, desire to limit ourselves except as may be pointed out in the appended claims,

What we claim as new and desire to secure by letters Patent, of the United States is:

1. A transformer comprising, a coupling medium' of magnetic material, and a plurality of high potential and low potential windings interleaved one within the other on said coupling medium and atleast one of said high-potential windings having a disproportionately large numberof turns therein.

2. A. transformer construction in accordance with claim 1 in which said high potential windings and low potential windings are symmetrically arranged in groups with respect to said coupling medium, thev low potential sides of said groups being adjacent said coupling medium.

3. A transformer construction comprising a magnetic, core, aplurality of inter-leaved windings, each having a difierent mean internal diameter and disposed one within the other, said windings being conductively interconnected in two .orders to form a high potential system and a said high potential and low inductively related, and

said high potenlow potential system,

at least one of said windings in .tial'systemof windings having a preponderance of t therein.

49A transformer construction in accordance with claim 3 in which the number of turns in at least one of said high potential windings is substantially the same as the number of turns in at least two other windings in said high potential system. p

5. A tormer construction in accordance with claim 3 in which least one. of said high potential windings is substantially equal to the number of turns in at least two other windings in said high potential system and in which said windings are all so positioned with respect to said core as to produce a region of substantially zero trtted potential adiacent the center of said core when potentials are delivered tosaid high 6. A transformer construction comprising, a plurality of conductively interconnected high potential windings, a plurality of 'conductively interconnected low potential windings inter-leaved one within the other with said p ings, said low potential windings all com .11.; substantially the same number of turns andcertain of said high potential windings difiering con= siderably inthe number of turns th.

7. A transformer construction in accordance with claim 6' in which at least one of said primary windings contains substantially twice the number of turns appearing in at 1 two others of said primary windings.

8. A transformer construction comprising a magnetic core, a plurality of individual windings di one within the other on said core. said potential system of wind windings being conductively interconnected to form two inductively related separate systems, the individual windings in one system each having substantially the same number of turns and the individual windings in another of said systems having substantially disproportionate numbers of turns.

9. A transformer construction in accordance with claim 8 in which one of the individual windings in said disproportionately characterized system of windings has a number of turns substantially equal to the number of turns in all of the other individual windings conductively connected therewith.

10. A transformer construction comprising, a magnetic core, at least two groups of windings one upon the other on said core, the windings in each of said groups being alternately conductively interconnected to form a primary system embracing both groups and a secondary system embracing both groups, the relative potentials in each group decreasing in a direction towards said magnetic core, the highest potential windings in said groups having a substantially greater number of turns than the windings of relatively lower potentials.

11. A transformer construction in accordance with claim 10 in which the higher potential windings in any one of said groups have substantially the same number of turns as all the other windings conductively connected therewith in said group.

12. A transformer construction in accordance with claim 10 in which the highest potential winding in either of said groups has substantially half the number of turns of the windings conductively interconnected in said group. i

13. A transformer comprising, a core of magnetic material, a plurality of groups of windings on said core, each of said groups comprising high potential and low potential windings inter-leaved, similar windings in all said groups being conduc- 10 tively connected to form separate inductively related high potential and low potential systems and the windings comprising each of said groups vbeing of different mean internal diameters whereby they are disposed one within the other.

14. A transformer comprising, a core of magnetic material, a plurality of groups of windings on said core, each of said groups comprising interleaved high potential and low potential windings, similar windings of all said groups being 20 conductively-connected to formseparate inductively related high potential and low potential systems, at least one of said high potential windings in each group having a disproportionately large number of turns, and the windings compris- 25 ing each of said groups being of diiferent mean internal diameters whereby they are disposed one within the other.

HENRY R. BUTLER.

JOHN L. WESTON. 30 

